The present invention relates to a display panel to be used for displaying advertisements, traffic information, etc., and to an indicator that constitutes such a display panel.
The above type of indicator has a plurality of light-emitting diode elements. And in an indicator proposed in Japanese Patent Application Unexamined Publication No. Hei. 2-6779, a plurality of light-emitting diode elements are disposed in a cylindrical outer case so as to be retracted from its opening plane by a predetermined distance. With this arrangement, the indicator is not exposed to the weather even without a glass plate etc. to cover its front surface. Since no front glass plate is employed, there does not occur such a problem that the glass plate reflects light coming from the front.
However, since the distance between the opening plane of the outer case and the light-emitting diode elements is fixed, the above-described conventional indicator has a problem that it cannot properly accommodate an environment and conditions in its actual use. For example, when ambient light comes from above or the indicator is directed to the north, it is preferred that a cover be provided above the light-emitting diode elements and that in the lower part of the indicator the diode elements be exposed almost completely, to effectively utilize light emitted from the light-emitting diode elements. On the other hand, when ambient light enters the indicator after traveling a path generally in parallel with the indicator, it is preferred that the light-emitting diode elements be shielded sufficiently. The above conventional indicator can accommodate only one of these situations.